1) The crystal structure of the bifunctional enzyme complex,tryptophan synthase, has been refined at 2.4A resolution. 2) Two inhibitor complexes of the Rhizopuspepsin have been analyzed by X-ray diffraction. Both complexes have been refined and the structures analyzed in terms of the probable mechanism of action. 3) Endonexin II, a calcium- and phospholipid-binding protein isolated from human placenta, has been successfully crystallized. X-ray diffraction data have been collected from native and heavy-atom treated crystals, and their space group has been determined.